Aerosols have an outsized influence on climate through their interactions with light and clouds. Solar radiation management (SRM) strategies propose to intentionally inject these tiny nanometer-scale particles into the atmosphere to increase Earth’s albedo and induce global cooling, as has been observed following major volcanic activity. While the ethics of SRM remain a topic of intense debate, it is essential to understand the relevant science in the event that SRM is deemed necessary to deploy. To inform hypothetical SRM campaigns, we must determine precisely how aerosols of different size and composition scatter and absorb light and nucleate cloud droplets. Here, we will harness cavity-enhanced frequency comb spectroscopy for broadband measurements of the optical properties, droplet nucleation dynamics, and chemical aging of SRM-relevant aerosols. Our results will provide direct inputs to global models and facilitate accurate simulations of potential climate interventions.